DISSERTATION RESEARCH: Islands on Islands on Islands: Bacterial Metacommunity Evolution in a Prairie Dog Landscape

跳蚤可以把致病的细菌从一种动物带到另一种动物，从野生动物带到人类。跳蚤是否能够成为病原体的有效载体取决于许多不同的因素。这一过程中被忽视的一个方面是生活在跳蚤肠道内的细菌群落的动态。跳蚤携带的不是单一种类的细菌，而是整个群落，细菌群落的组成和组装可能会影响跳蚤是否是有能力的载体。本项目旨在评估空间，时间和种间相互作用对感染草原土拨鼠的跳蚤内细菌群落组装的影响。 跳蚤是在2004年和2007年从生活在离散殖民地的动物身上收集的。 从数百只跳蚤中提取DNA，焦磷酸测序将用于从跳蚤DNA样本中产生数十万个细菌DNA序列。 这些细菌DNA序列将用于确定细菌群落是否在特定的草原土拨鼠菌落（空间）内，在特定的年份（时间）内更相似，以及细菌谱系之间的相互作用是否控制群落组装。 此外，系统发育技术将被用来与跳蚤和草原土拨鼠种群结构的细菌群落组装。这项工作将推进疾病载体内的细菌群落的动态研究，并将注意力集中在一个很少研究，但潜在的重要问题：即，是否载体内的细菌群落的组成变化显着，如果这种变化可以解释的变化载体的能力。此外，这项工作将与越来越多的重点描述和理解的微生物生态系统，是一个人的尾巴。

Fleas can carry bacterial agents of disease from one animal to another, and from wild animals to humans. Whether a flea is capable of being a competent vector for pathogens depends on a number of different factors. An overlooked aspect of this process is the dynamics of bacterial communities that live within the gut of fleas. Fleas do not carry a single species of bacteria, but an entire community, and the composition and assembly of the bacterial community may influence whether fleas are capable vectors. This project seeks to assess the effects of space, time, and inter-specific interactions on bacterial community assembly within fleas that infect prairie dogs. Fleas were collected in 2004 and 2007 from animals living in discrete colonies. DNA was extracted from hundreds of fleas, and pyro-sequencing will be used to generate hundreds of thousands of bacterial DNA sequences from the flea DNA samples. These bacterial DNA sequences will be used to determine if bacterial communities are more similar within a certain prairie dog colony (space), within a certain year (time), and if interactions between bacterial lineages govern community assembly. In addition, phylogenetic techniques will be used to relate bacterial community assembly to flea and prairie dog population structure. This work will advance studies of the dynamics of bacterial communities within disease vectors, and will focus attention on a little studied but potentially important issue: namely, whether the composition of bacterial communities within vectors varies significantly and if such variation can explain variation in vector competency. Furthermore, this work will dove-tail with the increasing emphasis on describing and understanding the microbial ecosystem that is an individual.